Digital imaging devices such as digital cameras typically comprise means for capturing an image, means for storing the captured image, and means for displaying the captured image to a user. The means for displaying the image to the user is conventionally a display screen such as a liquid crystal display screen or similar.
It is often desirable to process the displayed image or alter the properties of the displayed image (or the properties of the captured image) to allow a user to see a feature or features displayed in the image more clearly. Typically, the adjustable properties may include brightness, colour balance, contrast etc.
In a particular example, infrared sensing digital cameras are used to monitor the effective surface temperature of an apparatus to identify parts that are currently operational, overheating or under stress. Varying the range of and/or the maximum or minimum surface temperatures displayed in a captured image, allows particular parts at different temperatures to be identified more clearly. This thus enables a person to monitor operation of the apparatus more easily and to detect parts at risk of failure earlier.
To enable this control to be achieved, the imaging device is provided with control means for altering the properties of the displayed image or the properties of the captured image. Conventionally, such control means are embodied as control knobs or switches actuated by twisting, pressing or sliding as appropriate.
Use of conventional control means to vary image properties can however be less than convenient for a user. In particular, if the user wishes to select one of a number of properties to vary or wishes to vary only one end of a range of an image property, then unless the device is provided with a large number of individual switches it is difficult for a user to rapidly and accurately vary the image properties. Additionally, provision of a large number of mechanical switches adds significantly to the size, weight, and cost of such a camera whilst also significantly detracting from the ease of carriage and reliability for such a camera, particularly if the mechanical switches are adapted to function in a harsh environment.
It is thus an object of the present invention to provide an improved means for controlling the properties of an image displayed on a display screen.